Influence of Water-Soluble Gas Releasing on Gas-Water Interface forYinggehai Basin High Temperature and Overpressured Gas Field
Ma Yongxin
Xiao Qianhua
Mi Honggang
Qi Zhilin
Huang Xiaoliang
Ren Xingming
Abstract：Yinggehai basin X area belongs to high-temperature and high-pressure gas reservoir, so that the content of dissolved gas in water is very large.However, the changing characteristics of gas-water interface and water invasion regularity is unknown because of the releasing of dissolved gas in water.In this paper, the variation of dissolved gas in water of different formations in X was tested through PVT facilities using natural gas and formation water.The sand packed model with visualization was designed to investigate the influence of water-soluble gas on gas-water interface.Results show that the solubility of water-soluble gas is affected by temperature, pressure, salinity and the components of natural gas, gradually increases with the increase of pressure, decreases with the increase of the temperature at first and then increases and the inflection point temperature is about 80-90℃.The solubility of water-soluble gas is 22.5m3/m3, and 8.7m3/m3 for X-1 and X-2 under condition of 145℃, 54MPa respectively.Sand packed model with visualization experiment shows that the gas-water interface increases obviously in the process of natural depletion because of migration with gas releasing from the water, the pressure decreasing of formation water and capillary force.Numerical simulation of gas reservoir shows that gas-water interface of reservoir with high solubility of water-soluble gas increase faster and the water breakthrough time is earlier than those reservoirs with low solubility of water-soluble gas.During 10 years forecast period, water breakthrough in X-1 is about 800 days earlier, 800m faster on the plane and 7.3m faster on the vertical, considering water-soluble gas.And for X-2,those are 300 days, 500m and 7.0m respectively.
Keywords：high-temperature and high-pressurenatural gas fieldwater-soluble gasgas-water interfacesand packed model with visualizationpetroleum geology
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 1340-1347 )